Treating of animal-skin products



Patented Oct. 7, 1930 UNITED STATES.

PATENT] OFFICE ANTONIO FERRETTI, OF MILAN, ITALY, ASSIGN'OB TO SOCIET'A INVENZIONI BREVETTI ANONIMA TORINO, OF TUBIN, IT ALY TREATING OF ANIMAL-SKIN PRODUCTS No Drawing. Original application filed May 24, 1929, Serial No. 365,780, and in Italy July 14, 1928.

Divided and this application filed fluly 15, 1930. Serial No. 468,124.

' This invention relates to a process of treating animal skin materials or animal skin products, as distinguished from the treatment ofwool, hair, -etc., and has for one of its-objects the provision of a process adapted for utilizing untanned hides and scraps and cuttings therefrom, whereby such ma terials may be converted into a useful and valuable product which in appearance, fi-

brous texture and flexibility resembles natural leather.

It will be apparent that my invention is of great economlcal value in that it salvages or utilizes material which heretofore generally has been converted into glues or fertilizers, or simply thrown awa In the practice of my invention the untanned fibers of the material being treated are intimately admixed with an aqueous medium until a thin flowing slurry of the fibers in aqueous suspension is obtained. The proportion of aqueous medium to the material being-treated is necessarily large so as to obtain the desired-thin flowing mass or slurry. i

To this slurry I add a mineral tanning agent, afiber lubricant and a suitable binding material containing a Water insoluble binder, the binding material being miscible with Water prior to the coagulation ofthe binder, for example indiarubber latex", gutta percha latex, balata latex, or the like, as obtained from trees or plants and which may have been preserved by ammonia or any other suitable alkaline preserving material.

' A synthetic latex or other binding material containing a water insoluble binder and which is in suitable condition for incorporation in the slurry may be substituted for the latices above mentioned.

When latex is used as a binding material I-avoid the vulcanizing treatment otherwise required for preserving the latexby adding a vegetable tannin such as those of the pyrogallic series, more particularlysumac, to the slurry, this it being understood in addition to. the .mineral tanning agent above mentioned. As a mineral tanning agent or material I can employ particularly those containing chromium.

such as ammonium chloride or the like, the

addition of this material promoting the extracting of the liquid of the slurry and being of material advantage in the making of sheets of substantial thickness. 'In other.

words, the addition of ammonium chloride directly after the latex and before abstracting the liquid of the slurry improves the process and the product.

The slurry is then caused to flow upon a perforated support such as a Wire gauze and the liquid of the slurry abstracted so that a sheet of fibers is obtained. This material is then rolled and pressed and subjected to theusual finishing operations employed in the finishing of natural leathers.

I It is to be understood that the amount of "ammonium chloride employed will vary depending upon the material being treated and also depending upon the separation or abstracting of the liquid of the slurry that I a to the slurry.

.This application is a division of my copending application Serial N0. 365,780, filed May 24, 1929.

What I claim is 1. The process which comprises adding a mineral tanning agent and a grease to a flowing aqueous slurry containing the fibrous portions of untanned animal skin products in suspension, adding ammonium chloride, a Water insoluble binder and a preservative therefor to the slurry, and abstracting the liquid of the slurry.

2-. The process which comprises adding a mineral tanning agent and a grease to a-flowing aqueous slurry containing the fibrous portions of untanned animal skin products in suspension, adding ammonium chloride, rubber latex and a preservative for the rubber of the latex to the slurry, and abstracting the liquid of the slurry.

3. The process which comprises adding a mineral tanning agent and a grease to a flowing aqueous slurry containing the fibrous portions of untanned animal skin products in suspension, adding ammonium chloride and thereupon a water insoluble binder and a preservative therefor to the slurry, and abstracting the liquid of the slurry.

This specification signed this 21st day of June, 1930.

ANTONIO FERRETTI. 

